This invention pertains to antennas. More particularly, this invention pertains to vehicle mounted fiberglass whip antennas for use with citizens band (CB) frequencies.
When a CB whip antenna is mounted on a vehicle, the vehicle serves as the ground plane for the antenna. Consequently, the size of the vehicle and even the location of the antenna on the vehicle can affect the resonant frequency of the antenna and thus the performance of the antenna in the frequency band of interest. It is therefore desirable to be able to "tune" a citizens band antenna after it is mounted so that its resonant frequency is at the midrange of the frequency band of interest. Conventionally, such tuning is accomplished by varying the length of the antenna. This is generally inconvenient in the case of fiberglass antennas wherein a wire is coiled around a fiberglass core.